1. Technical Field
The present invention relates generally to an embedded system, and, more particularly, to an apparatus and method for recovering the file system of flash memory in an embedded system when damage has occurred to the file system of the flash memory.
2. Background Art
Various electronic systems have been integrated in cars. Real-time control applications, such as an electronic trunk release, an electric mirror adjustment device, rain detection, a sun roof, a weather condition management device, power windows, a seat adjustment device, a power train, stability control (an Anti-lock Braking System (ABS), towing control, and an active suspension), engine management and transmission, and a multimedia devices, such as an Internet terminal and a digital Television (TV), are installed and used in cars.
Electronic systems, including multimedia devices, navigation devices and telematics devices, are kinds of embedded systems.
The invention described herein features embedded systems equipped with NOR flash memory, comprising boot Programmable Read-Only Memory (PROM) for storing a normal state check value for a Cyclic Redundancy Check (CRC) and a Central Processing Unit (CPU) set such that it jumps to the boot PROM at a time of startup of the embedded system. FIG. 1 is a block diagram of a conventional embedded system, and FIG. 2 is a flowchart showing operation of an embedded system to provide the reliability of NOR flash memory.
Referring to FIG. 1, in certain preferred embodiments, an embedded system 100 basically includes a Central Processing Unit (CPU) 110, Synchronous Dynamic Random Access Memory (SDRAM) 120, which is volatile memory, NOR flash memory 130 for storing applications, and storage 140 for storing a large amount of data (such as navigation map data and multimedia files). In preferred embodiments, the storage 140 may be, but is not limited to, a Universal Serial Bus (USB), a Compact Flash (CF) card or a Hard Disk Drive (HDD).
Referring to FIG. 2, after the embedded system 100 starts at step S200, whether a failure has occurred in the NOR flash memory 130 is determined at step S210. Since the NOR flash memory 130 is not indefinitely reliable, there is a possibility of the occurrence of an abnormality of power, damage to a file system attributable to Electromagnetic Interference (EMI), or physical/logical failure attributable to an erroneous application.
If it is determined that there is no failure when the determination of whether a failure has occurred is made, the embedded system 100 operates normally at step S220. However, if there is a failure, the entire embedded system 100 stops and cannot operate any further at step S230.
In certain cases, an embedded system requiring high performance (a multimedia device, a navigation device, a telematics device or the like) is equipped with an Operating System (OS), flash memory for storing applications, USB memory for storing a large amount of data, and high-capacity storage, such as a CF card or a HDD. This means that the embedded system, requiring high performance, has a higher possibility of failing than a microcomputer-based system.
Meanwhile, there is no method of preventing the stoppage of the entire embedded system in an abnormal operational state (for example, in the case in which a logical failure, such as abnormal power, damage to a file system due to EMI, or damage to a file system due to an erroneous application, has occurred).
The above information disclosed in this the Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.